GAZA CITY - Britain's U.N. ambassador says there may be "an extremely short" humanitarian pause in the conflict in Gaza between Israel and Hamas on Saturday lasting several hours.

Mark Lyall Grant told reporters Friday that Britain is very disappointed at the failure to reach agreement on a sustainable cease-fire but perhaps a humanitarian pause "will open up a little bit of space to work on a more sustainable cease-fire."

U.S. officials later said Israeli Prime Minister Netanyahu had agreed to a 12-hour cease-fire in principle, but did not say if it came with a starting time. A Hamas spokesman, Sami Abu Zuhri, said the group agreed to a 12-hour lull, starting at 8 a.m. local time Saturday.

Lyall Grant said key foreign ministers will be meeting in Paris on Saturday "to decide precisely on the next steps."

Associated Press, Reuters, CNN and Yahoo! News reported that the cease-fire comes after Israel's Security Cabinet unanimously rejected a cease-fire proposal Friday that called for a week-long truce in the deadly conflict.

"Israel has agreed to a 12-hour ceasefire from 07:00 am Saturday," said a U.S. official traveling with Secretary of State John Kerry, according to Yahoo! News. Kerry was leaving Cairo without securing a longer cease-fire deal between Israel and Palestinian movement Hamas.

Kerry's proposal had called for a temporary pause in fighting to allow Israelis and Palestinians to broker a broader deal. Israeli TV reported the deal was rejected mainly because Israel would have to cut short its effort at destroying Hamas tunnels.

Kerry said some "terminology" on the truce's framework still needed to be worked out, speaking at an evening press conference in Cairo where he met with U.N. Secretary-General Ban Ki-moon and Egyptian Foreign Minister Sameh Shukri.

"We don't yet have that final framework, but none of us are stopping," he said.

A deal proposed by Egypt last week was rejected by Hamas because the group said it wasn't consulted. Hamas says any peace deal must include the lifting of a blockade against Gaza.

The failure of the new cease-fire proposal comes as five Palestinians were shot and killed in protests Friday in the West Bank after Palestinians called for a "Day of Rage" against the Israeli military's operation.

The circumstances surrounding the shootings in the northern village of Hawara and the southern village of Beit Omar, near Hebron, were not immediately clear.

Security was beefed up Friday in Jerusalem and the West Bank after thousands clashed with Israeli security forces Thursday night, leaving at least one Palestinian dead. Thursday's protests at a West Bank checkpoint and in East Jerusalem marked the largest demonstrations in those areas in several years.

Palestinians celebrate the announcement of a cease-fire on Aug. 26 in Gaza City. Palestinian President Mahmoud Abbas announced an Egyptian-brokered cease-fire proposal to end seven weeks of fighting between Israel and militant groups in the Gaza Strip. Mohammed Saber, European Pressphoto Agency

A Palestinian boy walks across the rubble of a house belonging to the al-Dakhani family after an Israeli airstrike on the Rafah refugee camp, southern Gaza Strip. Two people were wounded in the attack. Eyad Baba, AP

A man looks out the window of a damaged classroom after a rocket, fired by Palestinian militants from the Gaza Strip, landed in the courtyard of a kindergarten in Ashdod, Israel. Jack Guez, AFP/Getty Images

A Palestinian man sweeps the floor of his home that was damaged after a mosque across the street was hit by an Israeli airstrike in Beit Lahia in the northern Gaza Strip. Roberto Schmidt, AFP/Getty Images

A Palestinian woman watches from a hole in a home belonging to Hamas financial official Mohammed al-Ghul after it was targeted by an Israeli airstrike in Gaza City. One of several targeted airstrikes by Israeli forces killed Al-Ghul in his vehicle. Mohammed Abed, AFP/Getty Images

Relatives and close family friends of Daniel Turgeman touch his coffin during the boy's funeral on Aug. 24 in Yevul, Israel. Turgeman, 4, was killed in a mortar attack fired by Palestinians inside the Gaza Strip on Aug. 22. Jim Hollander, European Pressphoto Agency

Palestinians carry the body of the wife of Mohammed Deif, Israel's most-wanted man, at the Jabaliya refugee camp in the northern Gaza Strip. According to media reports, Deif's wife and son were killed Aug. 20 in an Israeli airstrike on Gaza City. Israel holds Deif, the leader of the Qassam Brigades, Hamas' military wing, accountable for directing the Gaza conflict from underground. Mohammed Saber, European Pressphoto Agency

Israeli soldiers in an undisclosed southern Israeli location take cover inside a cement pipe near the border with the Gaza Strip as a 'red alert' sounds, signaling that Palestinian militants have fired a rocket toward the area. The Israeli army reported that Palestinians shot about 180 rockets and mortars since the collapse of the cease-fire, with scores of Israeli strikes inside the Gaza Strip. Avi Roccah, European Pressphoto Agency

Palestinians grieve over the death of Widad Mustafa Deif, 27, and her 8-month-old son, Ali Mohammed Deif, during their funeral in Jabaliya refugee camp. They were killed by an Israeli strike Aug. 20. Khalil Hamra, AP

A Palestinian boy spots two Israeli drones in the late afternoon Aug. 19. Palestinians fled their homes in neighborhoods of eastern Gaza City carrying bags of clothes, pillows and mattresses after renewed Israeli airstrikes, witnesses said. Nine days of relative quiet in the skies over Gaza came to an abrupt halt when rockets struck Israel just hours before the truce was to expire at midnight local time. Israel immediately ordered a military response, with warplanes striking targets across the coastal strip. Roberto Schmidt, AFP/Getty Images

A rocket fired by Palestinian militants inside the Gaza Strip rises into the night sky. More than 50 rockets were fired toward Israeli civilian centers from Gaza on Aug. 19, shattering the 24-hour cease-fire, and Israel responded with multiple air force attacks on Gaza, with deaths and many casualties reported. Avi Roccah, European Pressphoto Agency

Palestinian rescuers clear the rubble of a destroyed house following an Israeli airstrike in Gaza City. The Israeli airstrike killed a young girl and a woman, wounding 16 other people. Mohammed Abed, AFP/Getty Images

An Egyptian soldier stands guard on the Egyptian side of the border between Egypt and the Gaza Strip on Aug. 13, overlooking the damage in Rafah caused by a month of fighting between the Israeli military and Hamas militants. Said Khatib, AFP/Getty Images

Palestinian mourners carry the body of Zakariah al-Aqrah, 21, during his funeral in the West Bank village of Qabalan. The Israeli military said it killed al-Aqrah early Monday morning after he opened fire on an Israeli force that had come to arrest him in connection with shootings targeting Israeli soldiers two weeks ago. Majdi Mohammed, AP

A Palestinian man standing in a crowd of onlookers reacts to watching a soap factory go up in flames moments after it was hit by an Israeli airstrike in Gaza City, Aug, 10. Roberto Schmidt, AFP/Getty Images

Palestinians search the debris of a house destroyed by an Israeli airstrike for survivors in the Beach refugee camp in northern Gaza City, on Aug. 4. The attack came minutes after an unilateral humanitarian ceasefire announced by Israeli forces, at least one eight year old girl died. Oliver Weiken, epa

Relatives take the bodies of four Palestinians from the hospital for burial, in Beit Lahiya, Gaza Strip. The four were killed in a missile strike outside their homes, according to the relatives. Dusan Vranic, AP

Palestinians evacuate a survivor after an Israeli airstrike hit the Al Ghoul family building in Rafah, southern Gaza Strip on Aug. 3. At least 40 people were believed to be inside the building in Rafah Camp when it was targeted by jet fighters, according to officials. Eyad Baba, AP

Blood is on the ground at a United Nations-run school after Israeli airstrikes in Rafah. At least 10 people were killed in the hit on the facility that was housing civilians. European Pressphoto Agency

Israeli Armored Personnel Carriers, part of a large column of tanks and other armored vehicles, redeploy into southern Israel on Aug. 3. Israeli ground troops began withdrawing from the Gaza Strip as Israel wraps up operations to destroy tunnels, but airstrikes continue. Jim Hollander, European Pressphoto Agency

Goats look for things to eat in the ruins of a housing complex in Beit Lahia, northern Gaza Strip. Human rights groups estimate that more than 10,000 houses have been destroyed or badly damaged by Israel. Oliver Weiken, European Pressphoto Agency

Israeli soldiers clean a 155mm artillery gun barrel at an army deployment area near the border with the Gaza Strip. Israel mobilized 16,000 additional reservists to bolster forces fighting in Gaza as Washington gave its ally the go-ahead to raid stocks of emergency U.S. weapons stored on Israeli soil. Gil Cohen-Magen, AFP/Getty Images

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The violence follows the shelling Thursday of a U.N. school, where at least 15 were killed and dozens wounded as the U.N. was trying to evacuate civilians in the northern town of Beit Hanoun.

The Palestinian Red Crescent said Israeli shells hit the school. The Israeli military said it was reviewing the incident and suggested Hamas-launched rockets may have been responsible for the deaths.

The conflict — in its 18th day — has killed 828 Palestinians and left 5,200 injured, said Ashraf al-Kidra, a Palestinian health official. In Israel, 38 people have been killed since July 8, including 35 soldiers, two Israeli civilians and a Thai worker.

The Israeli military said Friday that Oron Shaul, an Israeli soldier Hamas claimed to be holding, was in fact killed in battle Sunday.

In Tel Aviv, an Air Canada flight from Toronto aborted its first landing attempt Friday after Hamas fired several rockets toward Ben Gurion International Airport. But the Boeing 767-300 landed safely 10 minutes after the go-around and the airline plans to continue flying to Israel.

Five miles before landing, flight AC84 was advised by local air-traffic controllers to perform a standard go-around "until airspace conditions could be confirmed as safe for landing," said Isabelle Arthur, an airline spokeswoman. The plane landed safely at 12:07 p.m. and return flight 85 departed for Toronto at 1:59 p.m., Arthur said.

Meanwhile, Palestinian Justice Minister Saleem Al-Saqqa and Ismail Jabr, the Gaza court public prosecutor, filed a complaint to the International Criminal Court on Friday, accusing Israel of war crimes, including apartheid, attacks against civilians, excessive loss of human life and colonization.

Support for Hamas, in spite of the casualties — or some say because of them — is growing in Gaza.Early Friday, Israeli planes hit 30 houses throughout Gaza, including the home of Salah Hassanein, a leader of the military wing of Islamic Jihad, the second-largest militant group in Gaza after Hamas. Hassanein and two of his sons were killed in the strike, said Gaza police spokesman Ayman Batniji and al-Kidra. The Israeli army confirmed the strike.

"The problem is not with Hamas, the problem is the occupation," said Arafat Yasin, 46, a displaced resident from the Shijaeyyah neighborhood in east Gaza City that came under heavy bombardment last weekend. "The Palestinian Authority has been engaged in peace talks with Israelis for over 20 years, and the actions of the Israelis reflect their unwillingness to end their occupation."

"It's clear that they – the Israelis — are not interested in peace," he said.

Israel and Hamas, a U.S.-designated terrorist group that governs the Gaza Strip, have fought at least 10 wars and skirmishes in the past decade. The latest round of Gaza fighting began July 8 and with the collapse of truce talks in Cairo, there's risk of protracted fighting. A look at events since the collapse of the talks on August 19.